Universal die sinking attachment for horizontal milling machines



April 16, 19:15. E. LWALL 1,997,891

UNIVERSAL DIE SINKING ATTACHMENT FOR HORIZONTAL MILLING MACHINES Filed Dec. l2, 1933 4 Sheets-Sheet 1 E. L. WALL April 16, 1935.

UNIVERSAL DIE SINKING ATTACHMENT FOR HORIZONTAL MILLING MACHINES Filed Dec. 12, 1953 4 Sheets-Sheet 2 vENToR ,Em/Buncl L. Wall.

I ATToNl-:Ys

April 16, 1935.y E. l.. WALL 1,997,891 UNIVERSAL DIE sINKING ATTACHMENT FOR HORIZONTAL MILLING MACHINES Filed Dec. 12, 193s 4 sheds-sheet :s

E. L. WALL April 16, 1935.

UNIVERSAL DIE SINKING ATTACHMENT FOR HORIZONTAL MILLING MACHINES Filed Dec. 12, 1953 4 Sheets-Sheet V Edmund BY Am.,

ii/ ATTO EWITNESS Patented pr. 16, 19.35

UNITED STATES 1,991,891 n asin. nm smxmc. A'rTAcmIENT FOR HORIZONTAL Edmund Leo wall, Detroit, Mich.,

MILLING MACHINES assiznor, by

mesne assignments, to R. W. Glasner, Chicago,

Ill.

Application December 12, 1933, Serial No. 702,040

This invention relates to improvements in duplicating machines, and its objects are as follows:

First, to convert any horizontal boring mill, milling machine or lathe into a modelling or duplicating machine by use of relatively simple and inexpensive attachments, and this without disrupting the machine from its regular line of work.

Second, to enable any ordinary mechanic to perform the highly specialized work of a duplieating machine operator, the only requirement being a brief practice with the foregoing attachment to master its simple technique.

Third, to utilize the tracer mechanism of a companion application as the means for converting a known type of horizontal milling machine into a modelling machine, said mechanism automatically controlling the cutter bar or other profiling means and eliminating the chance of error on the part of the operator.

Fourth, to make the chief point of connection of the modelling attachment in such a Way that the conflicting weight pull and pressure fluid push are neutralized, the vonly additional strain on the spindle of the 4known machine being that of pushing the cutter to and from the Work.

Fifth, to provide a pair of simple cylinders and pistons for equalizing the pressure on the yoke in one direction, the fact of the cylinders being simple making for cheapness in manufacture, an additional advantage in their mode of connection with the head of the known machine being that they can be brought up a little closer to the head than in a companion application and so reduce the distorting strain on the vertical guides and boring bar to a minimum.

Sixth, to substitute the foregoing pair of cylinders for the single cylinder of the companion application and thereby facilitate the mounting of the necessary sheaves and the like by which the cables are guided to the point of connection with the yoke.

Seventh,-to interpose in the cable connection between the weight and yoke a multiple tackle system which materially reduces the weight as far as its pull on the yoke iscon'cerncd, so that a relatively low pressure pump can be used and a relatively low pressure maintained in the uid line, thus avoiding the necessity of having to use a high pressure pump both to counteract the back pressure on the iiuid line and avoid the danger of overheating the oil at high pressure.

Eighth, to provide a hand control in the nature of a three-way valve in the fluid line for enabling backing the tracer-cutter couple from the pattern and work should the need for doing so suddenly occur, or for initially moving the couple up to the pattern and work.

Ninth, to couple what might be called a precision measuring link between the cutter and vtracer means to enable an adjustment of said tracer means with respect to the cutter in the event of wanting to go over a cut for the removal of an additional amount of material from the work.

Tenth, to' couple the'tracer mechanism directly with the boring bar through the medium of rack and gear connections or their equivalents.

Eleventh, to provide the gib by which the boring bar is moved back and forth in the known machine with an extra rack to comprise one of the foregoing connections, the normal feed not being altered in any way although temporarily disconnected for the automatic operation herein contemplated.

In the drawingszv Figure 1 is a front elevation of the die sinking attachment on a horizontal boring mill which by use of the attachment is converted into a modelling or duplicating machine, the horizontal boring mill being shown in light lines.

` Figure 2- is a sectional view of a three-way valve which provides a hand control.

Figure 3 is a detail vertical section taken on the line 3-3 of Figure 1, chiefly' illustrating the adjustments of the tracer' cylinder with respect to its slide plate.

Figure 4 is a detail horizontal section taken on the line 4-4 of Figure 1.

Figure 5 is a detail front elevation of the yoke shown in Figure 1.

Figure 6 is a horizontal section taken on the line 6-6 of Figure 1.

Figure 'l is a cross section taken on the line 1-1 of Figure l.

Figure 8 is a cross section taken on the line 8-8 of Figure 1.

Figure 9 is a plan view of the apparatus seen in Figure 1. 1

Figure 10 is a cross section taken on the line Ill-i0 of Figure 1.

Figure 11 is a cross section taken on the line Il--li of Figure 10.

Figure 12 is a cross section taken on the line Figure 13 is an elevation of the foregoing precision measuring link, showing how it is coupled in the shaft between the cutter and tracer means.

v intended for a restricted class ot work, can have the advantage of an expensive modelling or duplicating machine, the addition of the attachment making it posible .to reproduce any patternl within the limits of the boring mill.

The horizontal boring mill which is herein used as an example is generally designated I. This includes a head 2 which'is movable up and down on guides 3. A long boring bar 4 is carried by the head 2. This bar is revolved by mechanism vinside of the head, but the nature of the specific mechanism is of no concern here. The boring bar is freely slidable endwise and it is one of the purposes of the attachment to cause the sliding.

A standard 5 of which the guides 3 are a part, rises up from one end (the right end) of a heavy iixed base 6. The standard 5 is surmounted by a sheave 1. A cable 8 is guided over the sheave, and it has a heavy weight 9 suspended from one end of it. One purpose of the weight 9 is to counterbalance the head 2, but instead of attaching the remaining end of the cable 8 to the head 2 as it is in the original machine, that free end is combined with a multiple tackle system the specic purpose of which is to lessen the pump requirements of the hydraulic or other pressure fluid element of the attachment necessary to counteract the weight 9.

A b ed l provides a pattern and work support. The pattern I and work I2 are secured to the bed one above the other. 'I'he fundamental object of the modelling attachment is to reproduce the profile of the pattern in the work, and for the latter purpose the boring bar 4 carries a cutter I3. The bed I0 is mounted on a table I4. This has a cross feed I5, either mechanically or manually operated, for steadily moving the bed 0 crosswise of the base 6 first in one direction and then in the other. This movement occurs directly with respect to a carriage I6 which is longitudinally adjustable along the base 6.

Attention is directed to the details oi.' the attachment. This begins with a tracer valve casing I8. 'I'he principle and construction of this valve casing are fully disclosed in my copending application, iiled February 26, 193.1, Serial No. 518,528. Essentially it contains a piston type valve plunger 23 (Fig. 1). This is in the nature of a sleeve or spool valve which is movable `end- Wise in the valve casing I8 by the uctuations of a tracer tip 39.

Actual details of the tracer mechanism of which .the valve casing I8 is a part are disclosed in my co-pending application, led December 12, 1933, Serial No. 702,039. These details include an extension tracer bar 43 (Fig. 1) by which the tip 39 is revolubly carried. This bar has a mid- -bearing or fulcrum 48 in a tube 52 which is sethe valve structure. 'Ihis rodhas a stop near thet outer end. Its purpose is that of an automatic iluid release, and in operation it prevents the cutter I3 from reaching a low point and therefore from damaging the bed I0.

There are pressure fluid inlet and outlet openings in the valve casing I8. These are designated 91, 08. A uid pressure pipe line includes pipes 99 and |00. 'I'he first is the supply, the second the exhaust. It is the purpose of the valve plunger 23 to control communication between the inlet 31 and outlet 98. The valve structure is an increment` of the tracer tip 39, and the extent ot rising'and falling of the latter over eminences and into depressions on the face ol the pattern I| determines the amount of opening and closing of the pipe line through the tracer valve casing I8.

A groove 0| (Figs. 1 and 3) von the underside of the tracer valve casing I8, or more properly on the underside of the heavy bottom of which the tracer cylinder is a part, receives the rib |02 (Fig. 5) oi.' a yoke |03. This yoke appears like an inverted L (Fig. 3) Its long vertical leg exltends down in iront of a standard I 04. This standard' carries a bracket |05 (Fig. 1) with which the stop on the rod 8| is engageable to cause the automatic uid release previously mentioned. The vertical leg is designated |08. The short horizontal leg is designated |01. It is this leg which has the rib |02, and both the leg and rib are slotted at |08 (Fig. 5) to receive bolts' |09 by which the cylinder is secured to the yoke. A hole IIO (Fig. 5) in the leg |06 communicates with the slot |08 and provides a placethrough which to get at the heads of the bolts.

The leg |06 is slotted up its middle at (Fig. 5) to make room for an adjusting screw ||2 as well as to provide guides for a spline ||3 (Fig. 4)

with which the screw has a threaded connection. The spline is part of a block 4. 'Ihe screw has a swivel connection with the bottom end of the yoke |03, and the means which comprises the swivel connection includes a knurled` hand wheel ||5 by which to turn the screw when turning is permitted. The-purposeof turning the screw is to raise and lower the tracer valve casing I8 and its immediately carried parts.

The block I4 is recessed at ||6 to receive the yoke |03. 'I'he spline ||3 stands out from the bottom of the recess and fits in the slot |I I as already brought out. The recess I|6 produces sides I1 which flank the vertical leg of the yoke. The height of the spline ||3 is approximately equal to the height of a clamp plate IIB (Fig. 5). The ends of this have holes to receive bolts ||9 by which the yoke is clamped tightly against the block ||4.

These bolts screw into a nut plate |20 (Figs. 3 and 4) which ts in the passage I 2| behind parallel tongues |22 respectively in and on a transversely `slidable slide plate |23 (Figs. 1 and 3). This lplate is freely slidable in the ways |24 of the standard |04. When the plate |23 slides in its vways the tracer cylinder |8 moves with it because the clamping arrangement by which the yoke |03 is attached to the slide plate virtually makes it and the tracer cylinder a single unit. Vertical adjustments of the tracer cylinder with respect to the plate |23 are made by rst loosening the bolts ||9 and then turning the hand wheel ||5. Horizontal adjustments are made by looseningthe bolts ||9 and shifting the nut plate |20 in the passage I 2| to a new place.

A rack bar |25 is secured to the slide plate |123 as at |`2li (Fig. 1) The bar is round in cross sec- |33 in the existing machine.

tion, but a part of it is attened at |21 (Fig. 3) where it lies against the plate |23. The free rack end of the bar |26 meshes with a gear |22 on the upper end of a shaft |29. This shaft has a similar gear |30 on its lower end (Fig. 1). The

`shaft |29 is supported in suitable bearings, one

of these being carried by an arm I3| (Fig. 1) which extends out from the standard |04. A precision measuring link, later described in detail, is coupled in the shaft |29 to enable adjustments of the tracer means relatively to the cutter.

The gear |30 meshes with a rack |32 (Figs. 1 and v12) on the side of what is known as a gib This gib already has a rack |34 on top. A hand wheel |35 (Fig. 9) known as the spindle quick advance -and return on the existing machine has a gear wheel (not shown) in mesh withthe top rack |34 for the purpose of shifting the spindle |36 (Fig. 6) also of the existing machine back and forth. The provision of the side rack |32 (Figs. 1 and 12) is to be understood as the modication of the gib to enable the adaptation of the attachment. The hand wheel |35 (Fig. 9) is simply uncoupled from the top rack |34, and what was originally a manual function in shifting the spindle |361is now the automatic function of the tracer mechanism,

the latter being connected to the spindle by the gear |30.

Of necessity the gib |33 (Fig. 12) is xedly attached to the spindle |36 (Fig. 6). The attachment is made through an arm |31 (Fig. 12) by means of bolts (not shown). The foregoing shifting of the spindle |36 comprises endwise sliding in bearings |38 (only one shown) of the existing machine (Fig. 6). These bearings are housed in an extension |39 of the head 2 (Fig. 1). Inside of the spindle there is a sleeve |40 also of the existing machine. This has a close it on the boring bar 4. It is removably secured to it by a plurality of bolts I4I, the points of which enter depressions |42 in the boring bar.

There is a series of these depressions spaced lengthwise of the boring bar, the purpose of the series beingto enable adjusting the boring bar into any wanted position (within limits) with respect to the sleeve |40. In addition to making connection with the boring bar 4 the bolts 4| also secure one of a pair of collars |43, |44 to the sleeve |40. The collar |43 is separate but vthe collar |44 is integral with the sleeve. The collars are at the extremities of the sleeve, and there are thrust bearings |45 between them and the ends of the spindle |36.

Sliding motion is imparted to the spindle |36 through a yoke |46 (Figs. 6 and 8) which is part of the modelling attachment. The yoke is secured to the right end of the spindle by a plurality of set screws |41 (Fig. 8). The yoke includes side arms |48 to which the rods |49 of pistons |50 are secured.

These-pistons work in cylinders I5I. There is a pair of cylinders, as is obvious, and the pur--A pose of the pair is to equalize the push in the direction of arrows a, (Fig. 6) by force of the fluid pressure in the right ends of the cylinders.

This force tends to push the boring bar 41 left (Fig. 1), cutter I3 into the work I2, and the tracer tip 39 against the pattern Il.

The yoke |46 has diagonal offsets |52 (Fig. 8)

" for the attachment of the inner ends of cables |53. These cables arel guided over a suitably arranged set of sheaves |54 (Figs. 1 and 9). The outer ends of the cables are secured to a con-t nector |55 (Figs. 1 and 9) which, in turn, has

Leanser Y v 3 connected to it at a central point Ame end 0fv a single cable |56 constituting a takeoff. The

other'end of this cable is anchored to the head But before being anchored there it is trained over and under a pair of sheaves |56, |59 (Fig. l) which with the cable |56 comprise the multiple tackle system mentioned before. The sheave |59 is suspended from the free end of the cable 6.

. The sheave |59 is carried by a bracket |60 which -is secured to the head 2. The weight 9, acting through the various cable connections which finally end at the offsets |52 (Fig. 8), tends to pull the boring bar 4 to theright (arrow b, Fig. 6), the cutter I3 away from the work I2 and the tracer tip 39 away from the pattern I.

The weight and the pressure fluid counteract each other, but one may predominate over the other. The tracer mechanism does the controlling, either letting the weight or the-pressure fluid predominate. However, the tracer mechanism is controlled by the pattern II.

The cylinders |5| are part of a casting I6| (Fig. 6) which' is iianged at |62 to takebolts |63 by which the casting is xedly secured to the extension |39. The casting and consequently the cylinders are, therefore, fixed as far as endwise movement is concerned. That part of the casting next to the extension is morev in the nature of a box, being large enough as well as appropriately shaped (Fig. 8), to contain the yoke |46.

The pressure uidr pipe line, specically comprising the supply pipe 99 and the exhaust pipe actually includes more detailed structure. The pipe 99 has a exible section |64 connected in it (Fig. l) to accommodate the horizontal movements of'the tracer valve casing I8. The pipe 99 continueson to a common connection |65 (Fig. 9) which supplies the right ends of both cylinders |I with pressure fluid.V This is supplied by a. motor driven pump |66 (Fig. 9). The pipe leading from the pump is designated |61. This includes a flexible section |68 which accommodates upand down movements of the head 2.

The exhaust pipe |00 (Fig. 1)' is telescoped, the purpose being to adapt itself to the horizontal movements of the tracer valve casing I6. The bottom end of it enters a fitting |69 (Fig. 10) which is flangedI at and secured therethrough to the standard |04 by means of bolts |1|. The

.exhaust pipe enters the fitting through a gland |12 which is adapted to be loosened and tightened. The purpose of loosening is to enable adjustments of the exhaust pipe with respect to the fitting |69 when the cylinder I9 is adjusted along the short horizontal leg |01 (Fig. 3).

A continuation |13 (Fig. 2) of the exhaust pipe |00 discharges into a sump |14. The pump |66 draws the iluid from the sump and discharges it into the uid system under pressure. In practice there is a by-pass valve between the pump and sump for the return of fluid under excessive pressure. The continuation |13 includes a telescopic section (Fig. 1) which adapts itself to the up and down movements .of the head 2. A three-way valve |16 (Figs. 1 and 2) provides a hand control for superseding the automatic conat whichv the respective pipes |61, 99 and |13 make connection with thevalve housing. There is a handle |82 for turning the valve member into either of its two positions.V

Position c (Fig. 2) of the vhandle |82 places the passage |18 so that pressure fluid will flow into the pipe line 88 from the pump byway of the pipe |61 and ports |18, |88. The normal return flow of fluid occurs into theexhaust pipe |80 as permitted by theV valve structure 23. Should it be desired to suddenly back the tracer Vmechanism as well as the cutter from the pattern and work respectively the handle |82 (Fig. 1) is thrown over to position d, (Fig. 2) so that the passage |18 bridges the ports |86, |6|. Pressure iluid from the pipe line 89 is diverted directly in the exhaust continuation |13 into' which it iiows from the cylinders |5| with the force of the weight 8 behind it. i

At this place it is necessary to return to parts of the foregoing description to amplify some of its features. The yoke |46 (Fig. 6) is the chief point of connection of the modelling attach-- ment to the horizontal boring mill insofaras concerns the control of the -mill by the attachment.

Obviously it is necessary to impose pushes and pulls on the yoke |46 first by force of the pressure iiuid (arrows a, Fig. 6), second by force of the weight (arrow b), but these forces are so nearly neutralized by the yoke which constitutes a common connector that the only additional strain on the thrust bearing |45 and on the spindle |36 is that actually required to slide the boring bar 4 and move the cutter I3 to and from the work 2.

Note must be made of the fact that the cylinders |5| (Figs. 6 and 7) flank the boring bar 4. This is an arrangement incidental to the dual and equalized connection of the pistons |58 with the .yoke |46. The cylinders |5| have an important purpose other than the means for applying the force of .fluid pressure at two points of the yoke, namely that of providing convenient mountings for the sheave supports so that the positioning of these is facilitated with respect to the rest of the structure.

As far as the cylinders |5| are concerned these are of a simple nature, that is to say, they are plain cylinders which are readily manufactured by known processes. Even counting in the casting |6| it is possible to bring up the cylinder assemblage a .little closer to the head 2, more specically to its extension |39; than would be possble with the equivalent type of cylinder in the companion application 518,528. It is desirable to get the cylinders as closev to the'head sary work with but a relatively lowl fluid pressure in the pipe line. This is an advantage in that it materially reduces the effect of the weight 8 Iinsofar as its pull on the yoke |46 (Fig. 6) is concerned. The weight 8 weighs approximately four thousand pounds. Its original purpose was to counterbalance the head 2, but its present additionalpurpose is to pull the boring bar 4 to the right all as fullybrought out before.

It is desirable not to alter the existing machine any more than necessary, and if the machine were altered byv the substitution of a lighter weight then the machine would not be ready for ordinary boring. drilling and milling. Since the vhalfV the force .ferred to before.

-the

` the operator to reach the wheel weightisusedtopull on theboring barinopposition to the iluid pressure, it follows that if it were connected directly to the bar the requirement would be fluid four thousand pounds to balance. A

'Ihe multiple tackle system cuts the eective weight approximately in half. A two inch movement of the pistons |56 (Fig. 6) under fluid pressure would produce approximately only one inch of upward movement of the weight 6. Therefore, according to a common principle of leverage only required to directly move the weight 8 is necessary to be applied to the pistons |86.

Attention is directed to Figure 13. 'I'his illustrates the'so-called precision measuring link re- The device is actuallya mi- `crcmieter which enables top end of the shaft |28 with respect tothe bottom end. To this end the shaft is split at |83.

A gear |64, secured to the bottom shaft meshes with a pinion |85 on the shaft |86 of the knurled wheel |61. This shaft |88 which is secured to thetop shaft.

A circular boss |89, almost as great in diameter as the gear |84,` stands up from the gear and contacts Ythe underside of the plate |88 against which it is'loosely held by bolts |80.

'The heads |8| of these bolts occupy a circular T slot |92 are inserted Athrough at least one square hole |93, whereupon the heads are slid around to the proper radial positions where they will match with the holes in the plate |88 preparatory to final assemblage. Upon turning the wheel |81 the pinion |85 will walk around the gear |86 and cause turning of the plate |88 and top shaft relatively to the gear |84. The adjustment will shift the slide plate |23 and consequently the tracer means to the rightor left, usually to the right, with respect to the cutter I3, and the purpose of the adjustment is to cut a little more olf from the face of the work.

The operation is readily understood. 'Ihe head 2 (Fig. l) is movable up and down on its guides 3 with a Astep motion by means not disclosed. All of the step motions will either be in upward or downward direction. Therewill be a pause between each step of suiiicient length to give the tracer'tip 39 and cutter I3 time to traverse the pattern and work |2. The tracer tip and cutter remain stationary as far as movement crosswise of the base 6 is concerned. It is the table I4 which moves crosswise of the base, and this carries the pattern and work. with it. When the table |4has ceased movement in one direction the head 2 takesa step either up or down whereupon the table I4 moves crosswise in the other direction and so on until the entire pattern and work have been traversed.

In case it is desired to take off say an additional one fourth inch from the face of the work I2 the tracer tip 39 is moved away from the pattern by turning the wheel |81 (Fig. 13) counter-clockwise looking down. This operation shifts the slide plate |23 (Fig. 1) to the right andv carries the tracer means with it. The adjustment would occur in an instance wherein the cutter |3 is made to cut across the work and it is desired to take a little more material o from the work in the same position of the cutter. 'Ihe so-called precision link is located relatively low down on the shaft |28. This makes it easy for |81, and theprovision of the link eliminates the necessity of the in the gear and its boss. The bolts pressure at approximately fine adjustments of the is journaled on a plate operator climbing up on the machine and attempting to make an adjustment in the tracer p mount. It is not equipped for any precise measurements. In a few words, the precision link merely advances or retards the gear |28 (Fig. 1), and as a result merely advances or retards the tracer means.

The tracer and cuttermechanisms are harnessed together, so to speak, so thatthe movements of the two are identical. When the tracer tip 39 reaches a cavity in the pattern and therefore tends to go to the bottom of the cavity, the cutter I3 will cut into thework |2 until it reproduces the cavity. This is because the tracer mechanism is directly' coupled with the boring bar 4 through the medium of the rack |25, |32 and gear connections |28, |30 (Fig. 1). The manner in which this operation is carried out is easily explainedz- Imagine the pump |66 (Fig. 9) to be at work. This sets up a pressure in the pipe line |61, |63,

99 which can be traced to the right ends oi! the cylinders |5| (Fig. 6). As long as there is no outlet for the pressure iiuid from the pipe line it is easy to see that the volume of fluid increases in the cylinders I5 I and naturally with the pressure behind it pushesthe pistons |50 and the boring bar 4 to the left (arrows a, Fig. 6). Since the boring bar 4 is supposed to be revolving it follows that the cutter I3 will continue to cut directly into the work |2` until it is stopped.

That is where the pattern and tracer tip 39 come in. As long as the tracertip 39 is over a cavity the cutter I3 will continue its cutting operation. Imagine the tracer 39 to have reached the bottom of the' cavity. Its tendency is to keep on going because it is carried by the slide plate |23 which, in turn, partakes of the same movement as the boring bar 4.

Since the tracer tip is now stopped, the tracer valve casing I8 will move leftward relatively to it. This unseats the valve plunger 23 so as to open the inlet 91.. Instead of all of the fluid going to the cylinders 50, 5I some of it escapes into the exhaust pipe |90 by way of the outlet 98. This diminishes the' pressure in the cylinders |5| and enables the weight 9 to pull back on the boring bar 4 to an extent depending on the amount of escape or by-passing of pressure uid at the outlet 98.

Presently the boring bar 4 will stop moving leftward. The weight 9 now predominatesand tends to keep pulling the boring bar and tracer mechanism to the right. There is a limit to this because the spring (not shown) behind the valve plunger 23 always keeps the tracerctip 39 in contact withthe pattern, even though very lightly, and its constant tendency is to keep the valve plunger seated so that there will be no by-passage of pressure fluid from 91 to 98.

Now with the tendency of the boring bar and tracer mechanism to move to the right byforce of the weight 9 the pressure between the tracer tip and the pattern soon relaxes enough to let the valve plunger 23 close. It does not need to close all the way. It is on the amount of closing that relling of the cylinders |50, |5| depends, and if the fluid pressure is again exercised upon the pistons |50. the weight 9 will be overcome so that the boring bar and tracer mechanism are again pushed to the left.

Imagine the tracer tip 39 to be traversing the pattern, or what is the same thing the pattern traversing 'the tracer tip, and the tracer tip encounters an eminence. There would be an immediate opening of the valve plunger 23. The ressure fluid will be by-passed from the supply pipe 99 to the exhaust pipe |00. The reduction of pressure in the cylinders I5| (Fig. 6) has the same eiect as before. The weight 9 pulls the boring bar 4 to the right andlets the cutter I3 reproduce the eminence.

Suppose the tracer tip and cutter should reach the end of the pattern and work and for want of something to stop them should be permitted to drop oi. It has been brought out that the constant tendency of the pressure uid is to drive the tracer-cutter couple to the left. The ways |24 (Fig. 1) are xed insofar as that movement is concerned. If the tracer-cutter couple travels far enough to the left the stop on the end of the rod 8| will engage the bracket |05. The eiect will be to displace the valve plunger 23 to the right. This opens the pressure pipe line to the exhaust and stops the movement of the tracercutter couple to the lett.

Should a. sudden need arise for backing the tracer cutter couple from the pattern and work the operator has only to throw the handle |82 of the three-way valve |16 to the position d (Fig. 2). This ity-passes the fluid directly from the cylinders ISI and fluid system 99 into the sump |14.

Since the port H9 (Fig. 2 is now closed the pump pressure will not have an outlet into the uid system, consequently its by-pass or relief valve (not shown) will open under the excessive pressure and release the fluid into the sump |14. The local circulation will continue until either the valve handle |02 (Fig. 1) is shifted back to position c mg. 2) or the pump motor is stopped. The weight 9 will then operate to pull the couple to the right. Movement of the handle to the position c (Fig. 2) returns the couple to the pattern and work. The stopping of the pump |66 leaves the tracer-cutter le in any given position will provided the valve plunger 23 is closed, and if the pump` isstopped the valve plunger will presently close.

I claimz- 1. Means for converting a boring mill which has an endwise slidable, revoluble boring bar and cutter into a modehing machine, said means comprising Huid pressine controlled moving means to slide said bar in one endwise direction with respect to the work, moving means to slide said bar in the other endwise direction, and tracer means which is caused to vibrate by the prole of a pattern," said tracer means embodying a valve casing and a valve therein, the latter subject to the vibrations of the and by its responses permitting varying quantities of the ud past said valve to vary the force of one of the moving means.

2. Means for converting a boring mill which has an endwise slidable, revoluhle boring bar and cutter into a modelling machine, said means comprising pressm'e fluid operable means to slide said bar in one endwise direction with respect to the work, reversely movable means including a weight with connections to the har to slide saidbar in the other endwise direction, tracer means which is caused to vibrate by the profile of a pattern, and a conh'ol for the pressure fluid. operable means being responsive to the vibrations of the tracer to vary the effective force of the pressure fluid eperable means.

3. Means for converting a boring mill which has l bar in one endwise direction with respect to the work, reversely movable means including a weight to move said bar in the other endwise direction, attaching means by which common connection of the opposing pressure iiuid operable means and reversely movable means is made to the bar, tracer means which is caused to vibrate by the profile of a pattern, and a control for the pressure uid at which all of the force-applying means terminate and at which the conilictingforces are neutralized, said attaching means being carried by the boring bar, and tracer controlled means for varying the eifectiveness of one of the force-applying means at said attaching means and consequently vary the eiectiveness o1.' the other force-applying means on said attaching means.

5. Means for converting a boring mill which has an endwise slidable, revoluble boring barrand cutter into a modelling machine, said means comprising at least two force-applying means tending to move said bar in opposite endwise directions with respect to the work, attaching means at which all of the force-applying means terminate and at which the conflicting forces are neutralized, said attaching means being carried by the boring bar, and control means for varying the effectiveness of both force-applying means as regards their individual ability to slide the bar in one or the other endwise direction.

6. Means for converting a. boring mill into a modelling machine said mill having an endwise slidable, revoluble, boring bar with a rack-gib and cutter, said means comprising pressure iluid operable means to slide said bar in one endwise direction with respect to the work, a weight with connections to the bar to move it in the other endwise direction, the rack-gib moving as the bar slides, a tracer-operated valve structure to govern Y the pressure fluid operable means, the tracer being vibrated by the profile of a pattern, a slide plate which carries thevalve structure, and connecting means between the slide plate and rack-gib to make said plate slide as the boring bar slides and so automatically actuate the valve structure due to the stoppage of the tracer by the pattern.

7. In a boring mill which has a vertically guided head and a boring bar endwise slidable and revoluble with respect to the head, said bar having a cutter; means to convert said boring mill into a modelling machine comprising a slide plate and means by which it is slidably supported on the head, pressure iiuid operable means to slide said bar in one end-Wise direction with respect to the Work, a weight with connections to the bar to slide said bar Vin the other endwise direction, coupling means to couple the slide plate to the bar so that said plate slides as the bar slides, tracer means to abut a pattern and a valve structure tol control the pressure uid operable means, said structure abutting thetracer means, and means by which both the tracer means and valve structure are carried in common' by the slide plate.

8. In a boring mill havingan endwise slidable spindle and means for attaching it to the revoluble boring bar which has a cutter; means for converting said mill into a modelling machine said means comprising a tracer mechanism, means for coupling the tracer mechanism to the boring bar so that said mechanism moves as the bar slides, pressure fluid operable means to slide the sleeve in one endwise direction, a weight to slide said sleeve in the other endwise direction, a yoke secured to the lsleeve being the common connector for the pressureiluid operable means and the Weight,. and a valve structure for controlling the pressure uid operable means, saidstructure being included in the tracer mechanism and operable by the tracer thereof.

9. In a bor-ing mill having a head and an extension thereof', a spindle endwise slidable in the extension and projecting therefrom, a boring bar and means to attach the spindle to the bar, said bar'having a cutter; means for converting said mill into a modelling machine comprising at least one pressure fluid cylinder and means by which it is secured to the extension, a piston operable in the cylinder and means for securing it to the projection of the sleeve, a weight and connections also secured to said means, a pressure iluid line leading into the piston and said means in a direction opposite to the pull of the weight, tracer mechanism carried by the head, means coupling' said mechanism and spindle so that the two move together, and a valve structure includedih the tracer mechanism controlling the pressure fluid in the fluid line according to the vibrations of the tracer.

l0. Means for' converting a. boring mill which has an endwise slidable, revoluble boring bar and and cutter in to a modelling machine, said means comprising a pair of cylinders ilanking the boring bar and stationary relatively thereto, pistons operable in the cylinders, a pressure iiuid system to supply the cylinders and force the pistons in one direction, connecting means. by which the pistons are connected with the boring bar, a weight and a cable `ioined with the connecting means to pull it in the opposite direction, sheaves of which at least one is carried by the cylinders over which the cable is trained to the place where it is joined to the connecting means, a valve structure for controlling the pressure uid system, and a vibratory tracer for vibrating the valve structure.

11. Inra boring mill having a head, a boring bar endwise slidable with respect to the head;

lpressure fluid operable means to slide said bar tackle system for diminishing the effective iiuid,

pressure to counteract the weight, said system comprising at least one cable, individual means by which the opposite ends of the cable are attached to the head and connected with the bar, and a pair of sheaves over and under which the cable is trained respectively connected to the weight and attached to the head.

12. In a boring mill having a head, guides on which it is movable, a weight to counterbalance the head, and a boring bar endwise slidable with respect to the head; means for utilizing the weight to slide the boring bar endwise in one direction comprising separate cables of which one end of the first cable is secured to the weight and the respective ends of the second cable are anchored to the head and connected with the bar, a tackle system comprising 'sheaves respectively carried by the remaining end of the first cable and by the head over and under which the second cable is trained, and pressure iiuid operthe cylinder to push on ablelneans to slide the `bar in the opposite direction, said tackle system diminishing the effectiveness of the weight as regards the boring bar and cutting down the pressure necessary to v counteract the weight.

tions commonly joining the Weight, head vand boring bar, pressure fluid operable means to slide the boring bar in the opposite direction, and a multiple -tackle system included in said cable connections for reducing the effectiveness of the making the weight as regards the boring bar to approximately one-half.

14. In a boring mill having a vertically movable head, a counterweight for thehead, an endwise slidable boring bar revolubly carried by the head and a normal feed for sliding the boring bar endwise to and from the work; means to replace the normal feed and to convert the mill into a modelling machine, said means comprising a take off from the weight for sliding the bar in-one direction, pressure fluid operable means to slide the bar in the other direction, a tracer mechanism subject to vibration by a pattern, a valve structure which is correspondingly vibrated by the tracer of said mechanism to controll the pressure uid operable means, and means to couple the tracer mechanism to the bar.

15. In a boring mill having a head, a slidable boring bar revolubly carried by .the head, and a .normal feed for sliding the boring bar endwise to and from the Work; means to replace the normal feed and convert the mill into an automatic modelling machine comprising two force-applying means acting on the bar and tending to slide it in opposite endwise directions, one of said forceapplying means comprising pressure uid operable-means, a pressure fluid line and pump to supply said means with pressure fluid, and a manual valve in said line shiftable into either of two positions either to build up pressure in said pressure uid operable means by connecting in the pump or by cutting out the pump and en- -abling the fluid to exhaust from the line.

16. In a boring mill having a head, an endwise slidable boring bar revolubly carried by the head, and a normal feed for sliding said bar back and forth with respect to the head; a pressure fluid control for replacing the normal feed, said vcontrol comprising pressure iiuid operable means to slide the bar. in one direction, a weight resisting said sliding, and means to cause either the building up or lowering of pressure in said pressure fluid operable means thereby either weight subservient or predominant.

17. A boring mill having a head and a slidable boring bar revolubly carried by the head, guides on which the head is vertically movable, a tracer mechanism by which the mill is converted into a vmodelling machine, said mechanism including a slide plate, a standard mounted on the head hav-l ing ways to slidably carry said plate, and means to mount said tracer mechanism on the slide plate for adjustments in theY direction of said guides.

18. Tracer mechanism comprising a cylinder, a yoke by which the cylinder is carried, a slide plate which is slidable to move the cylinder back vand forth, ways on which-said plate is slidable, and means for clamping the yoke to the slide plate.

19. Tracer mechanism comprising a cylinder, a yoke carrying the cylinder, a slide plate which is movable to move the cylinder, ways on which said plate is slidable, clamping means to secure the yoke to the slide plate, and means to adjust the yoke with respect to the clamping means upcn temporarily loosening said clamping means.

20. A modelling machine comprising a cutter, tracer means to follow a pattern, apparatus which is controlled Yby the vibrations of the tracer means to make the cutter respond to reproduce the shape ,ofthe pattern in the work, and means to adjust .the tracer means independently of the cutter from any given position of the cutter to enable taking ofi an additional amount from the work in any' line of traverse of the tracer means and cutter.

21. A modelling machine comprising a boring bar, tracer means, an apparatus responsive to the tracer means and by its responses controlling the boring bar, and a micrometer adjustment coupled in said apparatus -to reduce an adjustment of the tracer means relatively to the boring bar.

22. In a boring mill having a vertically movable head, counterbalancing means for the head, and endwise slidable boring bar revolubly carried by the head and a normal feed for sliding the. boring bar endwise to and from the work; means,

to replace the normal feed and to convert the "mill into a modelling machine, said means comprising mechanism for causing the counterbalancing' means to slide the bar in one direction,`

by the head and a normal feed for sliding the boring barendwise to and from the Work; means to replace the normal feed and to convert the mill into a modelling machine, said means comprising mechanism for causing the oounterbalancing means to slide the bar in one direction, pressure fluid operable means to slide the bar in the other direction, a tracer mechanism subject to vibrations by a pattern,. a valve structure which is correspondingly vibrated by the tracer to control the pressure fluid operable means, coupling means between the tracer mechanism and said bar, and micrometer adjusting means included in said coupling means.

24. In a boring mill having a head, a slidable boring bar revolubly carried by the head,and a normal feed for sliding the boring bar endwise to and from the work; means to replace the normal feed and convert the mill into an automatic modelling machine comprising two force applying means acting on the bar and tending to slide it in opposite endwise directions, one of said force applying means comprising pressure fluid operable means, a pressure uid line and pump to supplyl said means with pressure fluid, and means controllable at will to build up pressure in said fluid pressure operable means by controlling the operation of the pump with respect to the line.

25. In a combination'with a boring mill having a head, an endwise sliding boring bar revolubly carried by the head; and a normal feed for sliding said bar back and forth with respect to the head; 'a pressure fluid vcontrol for replacing the normal feed, said control comprising fluid pressure operable means to slide the bar in one direction, means resisting said sliding, and means to cause either the building up or lowering of pressure in said pressure fluid operable means thereby either rendering the second recited means subservient or predominant.

26. A boring mill embodying a head and a slidable boring bar revolubly carried by the head, said head being also vertically movable, a tracer mechanism by which the mill is converted into a modelling machine, said mechanism including ai slide upon which the tracer mechanism is mounted for movement therewithand vfor movement with respect thereto in directions transverse to the direction of sliding movement of the slide and also transverse to the direction of sliding movement of the boring bar, means connecting the boring bar and the tracer slide for movement in unison, and means in said connectionrto ad- `iust the tracer means relative to the boring bar.

27. A boring mill embodying a headand a slidable bring bar revolubly carried by the head, said h ad being also vertically movable, a tracer mechanism by which the mill is convertedinto a modelling machine, said mechanism including a slide upon which the tracer mechanism is mounted for movement therewith and for movement with respect thereto in directions transverse to the direction of sliding movement of the slide and also transverse to the direction of sliding movement oi' the boring bar, means connecting the boring bar and the tracer slide for movement in unison, and a micrometer adjustment in said connection to adjust the tracer means-relative to the boring bar.

- EDMUND LEO WALL. 

